Research on Design Scheme of Metro Dynamic Stray Current Protection for Underground Pipelines

In recent years, the large-scale construction of subways has caused more and more serious dynamic stray current interference on buried oil and gas pipelines nearby.Effective protection of buried pipelines is necessary to reduce the risk of pipeline corrosion.Because the dynamic fluctuation of subway stray current brings difficulties to the actual test and design of protection scheme, there is still a lack of effective protection design methods under the interference of subway dynamic stray current.In this paper, a buried natural gas pipeline interfered by subway stray current was taken as the research object, and the protection design method based on the field drainage test was explored.Firstly, arranging monitoring points in the interfered pipe section, carrying out detailed 24 h continuous monitoring of dynamic DC interference parameters at multiple interfered locations, and finally analyzing the inflow and outflow laws of subway stray current in the interfered pipe section based on the analysis of monitoring data.On this basis, on-site drainage tests at different locations were carried out, and the subway stray current protection scheme for the interfered pipe section was determined based on on-site tests and related calculations.After the implementation of the scheme, the effect was tested and evaluated, results showed that the expected protection effect was achieved.This work could provide reference for the design of protection scheme for buried pipelines under subway stray current interference.